Bituminous sheet roofing and weatherproofing material



C. N. FORREST.

BITUMINOUS SHEET ROOFING AND WE ATHERPROOFING MATERIAL.

APPLICA ION FILED JULY 12,1919.

1 429 7280 Patentedsept. 19, 1922.

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Patented Sept. 19, 31922.

UNHTEH) stares CHARLES N. FORREST, OF RAHWAY, N

EW JERSEY, ASSIGNOR TO THE BARBER ASPHALT COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPOTION OF WEST VIRGINIA.

BITUMINOUS SHEET ROOFING- AND WEATHERPROOFING MATERIAL.

Application filed July 12,

To all whom it may concern:

Be it known that 1, CHARLES N. FORREST, a citizen of the United States, and a resident of Rahway, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Bituminous Sheet Roofing and Weatherproofin Material, whereof the following is a speci cation.

My invention relates to bituminous sheet roofing and weatherproofing material, and more especially to the type of material whose most highly developed form is represented by the flexible shingle with. granular facing now on the market. The same material is also used in continuous strips-laid overlapping like strips of tar paperand in shorter strips slit along one edge and laid overlapping in such a way that the appearance of individual shingles is produced. In all these forms, the material is used on walls as well as on roofs, and for weatherproofing purposes generally. It is my aim to produce a material of this character free, on the one hand, from various practical disadvantages of such material heretofore known, and having, on the other hand, certain positive advantages of its own.

The general type of material to which I refer is disclosed in the U. S. patents to H. R. Wardell, Nos. 813,336, and 851,331, granted Feb. 20 and Apr. 23, 1907, respectroofing described in these atents may be suffic1ently characterized for my present purposeyas comprising a base,

composed of a plurality of sheets of bitumen-impregnated fabric cemented together, and bituminous coatings on both sides of said base-whose function, inter alia, is to protect it from access of moisture or evaporation of its impregnating compound.

- One of-these protective coatings carries a of such roofing material surface of granulated material or grit that forms the weather face of the material.

Another example of this general type of material now on the market dispenses with the inner bituminous coat or backing.

Now so far as I am aware, all the forms hitherto known have been open to some or all of the'following disadvantages:

'When used in shingle shape or shingle strip, the material would not lie flat, but

1919. Serial No. 310,432.

sightly degree, the overlying layers of material did not sufliciently adhere 0r cling to those beneath, so that in a'high wind storm they were liable to blow up, or even blow away entirely.

Besides being peculiarly liable to the disadvantages mentioned, material without the bituminous backing absorbs moisture at its rear side and loses the impregnant of its fabric base by evaporation, with the result that the fabric base rots and causes the shingles to curl very pronouncedly.

I have found that by a backing of peculiar character and properties, all these disadvantages can be obviated, and the material can be given'the capacity for spontaneous adhesion between overlapping layers to such an extent that after laying they automatically become a practically unitary, watertight, weatherproof, fire-resistant covering. ll have also discovered a method of considerably hastenin and augmenting, upon occasion, the ad esion on which depends the unificat1on of the covering. How these and various other advantages can be secured through my invention will appear from the description hereinafter of the best forms and modes of execution and application at present known to me, while its real scope and essence will be indicated in my claims.

I have found that a thoroughly stable, strong, rugged, and satisfactory material, having the advanages of my invention in a high degree, can be produced with a base comprising a single layer of fabric, instead of the plurality of layers disclosed in the Wardell patents. A suitable fabric for this purpose is a sheet of bibulous paper or felt such as is commercially known as rag felt. A. continuous long strip of such paper is first saturated or impregnated with a pitch 7 or bituminous medium-such, for example, as Trinidad or Bermudez asphalt suitably fiuxed with petroleum. This may be done by immersion in a bath of the hot asphaltum at a temperature of from 300 F.- to 500 F.

for a sufficient length of time. After being drawn through this asphaltum bath, the felt passes between hot rolls that s ueeze out the excess of asphaltum, so as to cave the surface of the paper dry, and free from glossy spots or excess of asphaltum. This paper is then coated on one side with hot bituminous cement (such as steep roofing pitch or asphalt) at a temperature of 200 to 300 F. and straightway drawn under a scraper which removes all excess and levels the surface. Immediately after, while still hot, the cement-coated surface receives a liberal application of flaked or granulated slate or other suitable grit; this is pressed into the cement, so as to insure firm adhesion to the paper, by passage of the paper under a roller-or between rolls-with slight pressure. The excess of mineral is then thrown oil in any suitable manner.

The foregoing steps would complete the manufacture of unbacked bituminous weatherproofing material (such as referred to above) in accordance with one of the processes in use prior to my invention,-the material being forthwith cut to length or into individual shingles and packed for shipment. While such material is protected on its grit-covered face against absorption of moisture, etc.-, its exposed'back not only permits gradual evaporation of the constituents of the impregnating medium required to make it sufiiciently fluid to enter the pores of the paper, but also permits the fabric to begin to absorb moisture at once. This is because the felt cannot be absolutely and completely saturated without being left with a glossy surface to which the subsequent bituminous cement coat would not adhere firmly enough to stay in place when the material was heated by the sun after being put in service.

My invention involves, therefore, a special backing of material faced as described above or in any other suitable manner. This may be formed by applying to the back of such material a high-melting, rubbery type of bituminous coating, which may be composed of oxidized petroleum; a combination of hard native asphalt or, asphalts with petroleum flux; or stearine pitch. Whatever material be used. it is essential that it be water insoluble and water repellent, moderately hard, and have a melting point above 150 F. I have found that an oxidized asphaltic petroleum having a penetration of from 10 to 30 and a melting point of from 150 F. to 250 F., is a suitable bituminous coating for such use. The scale of hardness here referred to is of course, the penetration in 5 seconds at 7 7 F. of a No. 2 Roberts needle loaded 100 grams, American Society for Testing Materials standard method. It is applied hot to the roofing material beforeit is cut, in any convenient manner. A suitable method of application is to pass the sheet of saturated felt over a hot metal roller which is revolving in a tank of the melted bituminous material. i

.material shall constitute the cement binder for the facing.

Inasmuch, as bituminous shingles are shipped in bundles, and the back of one unit is in facial contact with the mineral covered surface of another and the bundles" are bound tightly together, it is obvious that a unique type of bituminous material must be used for the back coatin or the whole bundle of shingles will st1ck together before they reach the consumer.. The like applies,- also, to shingle strips and to rolls of continuous plain sheet material. As an extra precaution against sticking, the backs of the shingles may be dusted with finely powdered soapstone, talc, slate, or the like.

However, although sheet material faced and backed as above described will not stick to similar material under shipping conditions, nevertheless it will be found that under the natural influences and conditions of use, when the material undergoes rogranular mineral or other gritty longed exposure to the hot sun after laymg, .adhesion will occur spontaneously between the overlying back of one layer and the face of a subjacent layer to such a degree that the whole roof covering automatically becomes, in effect, one single unit,-so that the backing has a fixative function'additional to its protective one. This action can be augmented and hastened by application ofa suitable solvent to the back of each piece of material as it is laid or secured on the roof or other structure tobe covered, so as to soften the bituminous coating somewhat and render it readily and freely adhesive at once. This may be done very expeditiously and conveniently by wiping the back with a cloth or brush that has been dipped in kerosene.

In the drawings," Fig. I represents con-' ventionall the several layers constituting a sheet 0 .my roofing as though removed successively at one portion.

Fig. II 1s a corresponding cross sectional view taken at the line II-II in Fi I.

As herein shown, 1 represents t e bituminously saturated base; 2 the bituminous cement on the weather side of the base 1 and 3 the grlt thereby secured to the base; and 4 represents the fixative bituminous backing. y

Having thus described my invention, I claim:

1. A flexible bituminous sheet weather 18 proofing material comprising a fabric base saturated or impregnated with a bituminous medium; faced, on its weather side, with grit secured thereto with bituminous cement; and backed, on its inner side, with a water insoluble and repellent protective and fixative bituminous coating, sufficiently hard and high melting not to stick to a similar sheet under shipping conditions, but soft enough to adhere spontaneously to the facing of a subjacent similar sheet under. the natural influence and conditions of use when exposed to the hot sun.

2. A flexible bituminous sheet 'weatherproofing material comprisin a fabric base saturated or impregnated wit ,a bituminous medium; faced, on its weather side, with grit secured thereto with bituminous cement;

andbacked, on its inner side, with a water insoluble and repellent bituminous coating, moderately hard and high melting so as not to stick to a similar sheet under shipping conditions, but soft enough to adhere spontaneously to the facing of a subjacent similar sheet under the naturalinfiuences and conditions of use when exposed to the hot sun, and also capable of being rendered readil and freely adhesive to the facing of a sub acent similar sheet by slight application of a solvent.

3. A flexible bituminous sheet weatherproofing material comprising a fabric base saturated or impregnated with a bituminous medium; faced, on its weather side, with grit secured thereto with bituminous cement; and backed, on its inner side, with a water insoluble and repellent protective and fixative rubbery bituminous coating, with a hardness of about 10 to 30 and a melting point of from 150 F. to 250 F., so as not to stick to a similar sheet under shipping conditions, but to adhere spontaneously to the facing of a subjacent similar sheet under the natural influences and conditions of use when exposed to the hot sun.

4. A roofing material for buildings consisting of a plurality of rectangular units applied as shingles which, under the natural influences and conditions of use when exposed to the hot sun, are automatically and spontaneously stuck together, after laying, by a bituminous coating upon the back of the individual units. I

In witness whereof, I have hereunto signed my name at Philadelphia, Pennsyl- Vania, this ninth day of July, 1919.

' CHARLES N. FORREST.

Witnesses:

JAMES H. BELL, e

E. L. Fommnron. 

